Influence of inlet gas components on the diesel steam reforming of proton exchange membrane fuel cells for hydrogen production

This paper investigated the rates of diesel conversion and reforming over Ni-Yb/γ-Al₂O₃ catalyst (Ni 16%, Yb 5%) in low/high temperature diesel steam reforming with different inlet gases (CO₂, H₂ and CH₄) as well as the influences of CO₂ inlet gas on water-gas-shift and CO deep removal, which are the follow-up processes of the hydrogen production flowsheet based on diesel steam reforming for proton exchange membrane fuel cells (PEMFC). CO₂ or H₂ improves diesel conversion (> 95%) in low temperature (from 400 to 500℃) diesel steam reforming, which can let CH₄ instead of diesel to participate high temperature (from 550 to 750℃) steam reforming, so that carbon deposition can be resisted obviously. However H₂ shows depression on the high temperature steam reforming, and CH₄ inlet gas depresses diesel conversion. When the molar ratio of gas to the total carbon of diesel is around 0. 54, CO₂ inlet gas shows the best improvement on diesel conversion; however the CO content increases in the product gas, so the gas-hourlyspace-velocity of CO water-gas-shift should be reduced to reach the required CO removal ratio. There is no obvious influence on the two-stage methanation for CO deep removal.